We've just signed up for the SO hiring platform in order to contact willing candidates about a role we have going. In the process we've discovered that candidates actually need to go out of their way to enable a link to their SO profile (profile -> developer story -> edit top right -> pick network -> SO).
As both a hirer and a candidate this came as a pretty big surprise to me. It seems a shame to have built up a reputation on SO to not be able to use it when you're trying to get hired.
I thought I'd point it out in case anyone else was using the platform and hadn't enable that flag.
This isn't required in order to appear in search results by recruiters. As long as a user has their job search status set to either "Actively looking right now" or "Open, but not actively looking", they will be included in candidate search.
(source: I work for SO)